Physical Activity and Responses to Aerobic Exercise Flashcards
any bodily movement that comes about from the contraction of skeletal muscle and that increases energy expenditure
physical activity
5 major components of physical fitness
Mnemonic: MCFBM - My Cat Finds Black Marbles
1) Muscular Fitness (strength and endurance)
2) Cardiovascular / Cardiorespiratory Endurance (aerobic power or fitness)
3) Flexibility
4) Body Composition
5) Mind/Body Vitality
the maximal capacity of the heart, blood vessels, and lungs to deliver oxygen and nutrients to the working muscles so that energy can be produced
cardiovascular/cardiorespiratory endurance
components of lean body mass
bones, muscle, nervous tissue, skin, organs, and blood
essential body fat percentage for men
2-5%
essential body fat percentage for women
10-13%
health disorders associated with excess body fat
hypertension, type 2 diabetes, coronary artery disease
T/F: During exercise, the parasympathetic nervous system is inhibited and the sympathetic nervous system is stimulated.
True
the amount of time it takes for physiological processes that occur with the beginning of exercise to meet the increased demand for oxygen
2-4 minutes
systems (metabolic pathways) used to produce energy at the onset of aerobic exercise
phosphagen system and anaerobic glycolysis
at cessation of exercise, oxygen consumption slowly declines but is still above resting levels; energy used during this time replenishes depleted phosphagens, eliminate accumulated lactate, and restores other homeostatic conditions (thermoregulation, tissue resynthesis)
excess post-exercise oxygen consumption (EPOC)
exercise intensity is so high that steady-state aerobic metabolism no longer is sufficient to meet the metabolic demands and therefore the muscles have to supplement ATP production via anaerobic metabolism
anaerobic threshold (AT)
T/F: Once AT is exceeded, lactate accumulates progressively in the blood, the oxygen deficit and corresponding EPOC are extremely high, and exercise cannot be performed for more than a few minutes.
True
the first ventilatory threshold is also referred to as this
lactate threshold
the second ventilatory threshold is also referred to as this
respiratory consumption threshold (RCT) or onset of blood lactate accumulation (OBLA)
T/F: There is an increase in respiration in order to clear out or blow off excess CO2 and is referred to as the ventilatory threshold (VT).
True
first change in breathing pattern; first time lactate begins to accumulate in the blood, represents hyperventilation relative to VO2, and the need to blow off CO2 represented by the buffering of acid metabolites
first ventilatory threshold (VT1)
point where lactate is rapidly increasing and represents hyperventilation even relative to the excess CO2 that is being produced; blowing off excess CO2 is no longer adequate to buffer the increase in acid metabolites
second ventilatory threshold (VT2)
amount of time a well-trained individual can maintain VT1
1-2 hours
amount of time a well-trained individual can maintain VT2
30-60 minutes
measure of pressure in the arteries during the relaxation (diastole) phase of the cardiac cycle
diastolic blood pressure (DBP)
T/F: Most of the improvement in cardiac output that occurs with training is attributable to heart rate.
False
Attributable to stroke volume
process by which epinephrine causes the release of glucose from the liver to allow blood glucose levels to remain high to provide fuel for the exercising muscles
glycogenolysis
the benefits of any type of exercise program are said to follow this principle
SAID principle (specific adaptation to imposed demands)
changes to the cardiorespiratory system includes these 3 improvements
1) cardiac efficiency (increased SV and lower HR)
2) increased respiratory capacity
3) increased maximal oxygen consumption
the 3 cardiac output adaptations to cardiovascular training
1) decrease HR at any submaximal effort, including rest
2) increased SV at rest and all intensities
3) increased maximum cardiac output
the 3 oxygen extraction adaptations to cardiovascular training
1) increased capillary density
2) increased number of mitochondria
3) increased activity of mitochondrial (aerobic) enzymes
T/F: A higher ratio of blood plasma to red blood cells reduces the blood’s viscosity (thickness).
True
T/F: A physical performance advantage of reduced blood viscosity is that it enhances oxygen delivery to the active skeletal muscles since the blood can more easily flow through the vessels, including the capillaries.
True
T/F: Both heart size and heart volume decrease as an adaptation to increased work demand.
False
Both increase
used to determine the rate at which oxygen is being used during physical activity
Fick Equation
Fick Equation
Cardiac Output (HR X SV) X Arterial-Mixed Venous Oxygen Difference (Oxygen Extraction)
T/F: Regular endurance training decreases parasympathetic activity and increases sympathetic activity.
False
Parasympathetic activity increases and sympathetic activity decreases
T/F: As a result of the increase in mitochondrial size and number from endurance training, there is a slower rate of muscle glycogen utilization and a greater reliance on fat as a fuel source (glycogen sparing effect) which may allow the exerciser to maintain higher intensities for longer periods of time.
True
3 neurological factors that contribute to strength gains in the early part of a resistance training program
1) Motor unit recruitment and synchronization
2) Rate coding
3) Diminished co-contraction
the frequency of impulses sent to a muscle; increased force can be generated through an increase in either the number of muscle fibers recruited or the rate at which the impulses are sent
rate coding
a motor unit’s smallest contractile response to a single electrical stimulation
twitch
a series of multiple stimuli in rapid sequence, prior to relaxation from the first stimulus, resulting in even greater force production
summation
continued stimulation at even higher frequencies that summation, resulting in the greatest force production of a motor unit
tetanus
types of training beneficial to provoking increases in rate coding
ballistic (explosive) or rapid movement
also called the pacemaker
sinoatrial node (SA)
regulates heart rate; located in the posterior wall of the right atrium
sinoatrial node (SA)
two most prominent factors that influence heart rate
parasympathetic and sympathetic divisions of the autonomic nervous system
at rest, the heart is mostly under the influence of vagus nerves, referred to as…
parasympathetic tone
a decrease in the parasympathetic tone to the heart will have what effect to heart rate
increase / elevate
stimulation of these nerves causes the release of catecholamines and innervate the SA node and ventricles
cardiac accelerator nerves
the most important determinant in blood flow regulation to skeletal muscle during exercise
autoregulation
3 factors for why SBP is affected more than DBP during exercise
1) increase heart contractility and stroke volume increase the force with which blood leaves the heart
2) muscle action requires greater force or pressure to deliver blood into the exercising muscles
3) vasodilation of the exercising muscles allows more blood to drain from the arteries through the arterioles and into the muscle capillaries, thus minimizing changes in diastole pressure
3 ways in which blood volume is maintained during exercise
1) progressive increase in HR at steady-state exercise to maintain cardiac output and offset the small loss in stroke volume associated with fluid loss
2) further vasoconstriction of non-exercising muscles
3) release of vasopressin (antidiuretic hormone) and aldosterone to reduce water and sodium loss
T/F: Cardiac output is ultimately dependent on the volume of blood returned to the right side of the heart via systemic venous circulation (venous return).
True
During submaximal exercise, ventilation increases linearly with oxygen consumption and CO2 production, which occurs primarily through…
tidal volume
volume of air inhaled and exhaled per breath
tidal volume
T/F: Overcompensation in breathing frequency at near-maximal intensities results from an increase in CO2 output related to anaerobic glycolysis that predominates during near-maximal intensity exercise.
True
fast-acting hormones
catecholamines, insulin, and glucagon
slow-acting hormones
cortisol and growth hormone
these responses occur under epinephrine
1) increase in strength of cardiac contraction
2) vasoconstriction in non-exercising muscles
3) vasodilation in exercising muscles
4) dilation of respiratory passages
5) reduces digestive activity and bladder emptying
6) stimulates mobilization of stored carbohydrates and fats for use as energy to fuel exercise
7) stimulates production (gluconeogenesis) and release (glycogenolysis) of liver glycogen
8) increases blood fatty acid levels by promoting lipolysis for use as fuel
9) affects the CNS to allow for quick thinking to help cope with impending stressors
the production of glucose from non-sugar substrates such as pyruvate, lactate, glycerol, and glucogenic amino acids
gluconeogenesis
the breakdown of muscle and liver glycogen to yield blood glucose
glycogenolysis
the breakdown/release of triglycerides in adipose tissue to free fatty acids (FFAs) for use as fuel
lipolysis
T/F: Activation of the parasympathetic nervous system during exercise suppresses insulin release from the pancreas.
False
Sympathetic nervous system
stimulates FFA mobilization from adipose tissue, mobilizes glucose synthesis in the liver (gluconeogenesis), and decreases the rate of glucose utilization by the cells
cortisol
Prolonged elevations in blood cortisol levels have been linked with these 4 things
1) excessive protein breakdown
2) tissue wasting
3) negative nitrogen balance
4) abdominal obesity
promotes protein synthesis, supports action of cortisol by decreasing glucose uptake by the tissues, increasing FFA mobilization, and enhancing gluconeogenesis
growth hormone
chemical compound required for all cellular work
adenosine triphosphate (ATP)
T/F: Carbohydrate is the only macronutrient whose stored energy generates ATP anaerobically.
True
T/F: Glycogen is stored in both the muscle and liver, but blood glucose levels are regulated primarily through the glycogen stored in the liver.
True
T/F: The carbohydrate metabolized by muscle glycogen occurs before blood glucose derived from glycogenolysis occurs.
True
a series of chemical reactions that act to break down pyruvate to carbon dioxide, water, and many hydrogen-powered molecules known as NADH and FADH2
Kreb’s cycle
Rate of ATP production: very rapid Substrate: creatine phosphate, ATP System capacity: very limited Utilization: high-intensity, very short-duration exercise Limitations: limited energy supply
Phosphagen System
Rate of ATP production: rapid
Substrate: blood/muscle glucose, glycogen
System capacity: limited
Utilization: high-intensity, short-duration exercise
Limitations: lactic acid production
Anaerobic Glycolysis System
Rate of ATP production: slow
Substrate: blood glucose, glycogen, fatty acids, proteins
System capacity: unlimited
Utilization: lower-intensity, longer-duration exercise
Limitations: slow rate of oxygen production
Aerobic (Oxidative) System
fast-twitch fibers contain more of this than slow-twitch fibers which allow them to produce 10-20% more force
myosin
thick contractile protein in a myofibril
myosin
3 performance characteristics that determine muscle contractility
1) maximal force production
2) speed of contraction
3) muscle fiber efficiency
fibers containing high levels of this allow muscles to contract with higher speed
myosin ATPase
3 reasons why slow-twitch fibers are more efficient than fast-twitch fibers
1) higher concentrations of myoglobin
2) larger number of capillaries
3) higher mitochondrial enzyme activities
a compound similar to hemoglobin, which aids in the storage and transport of oxygen in the muscle cells
myoglobin
A reduction of this causes muscle fatigue
glycogen reserves
T/F: Metabolism increases 10-15 times above resting levels during intense aerobic exercise.
False
20-25 times
4 mechanisms the body uses to give off heat
Mnemonic: ERCC - Early Risers Catch Cats
1) Evaporation
2) Radiation
3) Convection
4) Conduction
heat loss in the form of infrared rays; transfer of heat from the surface of one object to another w/o physical contact
radiation
the sun’s rays transferring heat to the earth’s surface
radiation
transfer of heat from the body into molecules of cooler objects that come into contact with its surface
conduction
transfer of heat from the body to a chair while someone sits on it
conduction
heat is transferred to either air or water molecules in contact with the body
convection
when wind from a fan blows over the skin
convection
when heat is transferred from the body to water on the surface of the skin
evaporation
prominent form of thermoregulation at rest
radiation
prominent form of thermoregulation at rest
evaporation
fluid intake recommendations in and around exercise
1) 2 hours prior to exercise - 500-600 mL (17-20 oz)
2) During exercise, every 10-20 min, 200-300 mL (7-10 oz), or based on sweat loss
3) Following exercise, 450-675 mL for every kg of body weight lost (16-24 oz for every lb)
3 primary ways the body avoids excessive heat loss (particularly in cold environments)
1) peripheral vasoconstriction
2) nonshivering thermogenesis
3) shivering
stimulation of the metabolism (as directed by the sympathetic nervous system) to increase internal heat production
nonshivering thermogenesis
the most distinct difference in thermoregulation b/w men and women
sweating (evaporation)
women rely on these mechanisms to regulate body heat than men
radiation, convection, and conduction
